1. Field of the Invention
The present invention relates to an active material capable of improving the capacity retention of a battery.
2. Description of Related Art
Recently, information relating apparatuses and communication apparatuses such as a personal computer, a video camera, or a mobile phone have been rapidly widespread, and accordingly, high importance has been placed on development of a battery used as a power supply of the apparatuses. In addition, in the automobile industry and the like, development of a battery having high output and high capacity for an electric vehicle or a hybrid vehicle has been progressed. In general, a battery includes: a positive electrode active material layer containing a positive electrode active material; a negative electrode active material layer containing a negative electrode active material; and an electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer.
In order to improve battery performance, an active material used for a battery has been studied in various ways. For example, International Publication WO 2013/042706 discloses Br3-trioxotriangulene having a phenalenyl structure as an active material for a lithium ion battery. In addition, Japanese Patent Application Publication No. 2009-129742 (JP 2009-129742 A) describes that a cyclic compound is used as a negative electrode active material for a sodium ion secondary battery. Further, Japanese Patent Application Publication No. 2007-227186 (JP 2007-227186 A) discloses an organic compound having a phenalenyl structure as an active material for a lithium ion battery.
The present inventors have made a new attempt to use Bra-trioxotriangulene having a phenalenyl structure as an active material not only for a lithium ion battery but also for a sodium ion battery, and have found a new problem in that the capacity retention of the battery is not sufficient.